Tweaking the 6.0L 2500HD

9,763 Views | 28 Replies | Last: 6 yr ago by agwrangler2001
hurricanejake02
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AG
I recently bought an '09 Sierra 2500HD Z71 with 85k miles on the 6.0 (LY6, I believe?) - it performs fine for a 3/4 ton truck, but it's a slug. What are some quick/easy/cheap (I know, I know, pick two) solutions to make this thing a little more fun to drive, without robbing the towing capabilities?
Silvy
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AG
Tune and long tubes
hurricanejake02
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AG
After doing nothing for the last 2 years, I'm finally ready to get this tank rolling a little better. Any recommendations on long tube headers? Having a hard time finding ones designed for the 3/4 ton.

CAI worth the money or just a waste of time?
Silvy
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AG
Contact this guy regarding fitment of headers on your truck. I'm running their headers and Y-pipe on my DD and they're great.

sean@speed-engineering.com

Rather than a CAI, you can just get an Airraid Jr. intake tube.
hurricanejake02
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AG
Thanks for that, Silvy - Speed Engineering was able to point me in the right direction for a lot less money than I expected.

Who are you using for tunes? I was talking to Black Bear, but they suggested a single tune for both daily driving and towing, which didn't make sense to me. Even the off-the-shelf tuners have a different setup for performance vs. towing.
Silvy
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AG
I use a local guy that I've known for a while that does tuning on the side.

Blackbear is correct that there's only one tune, it's going to be the tune where you make the most power. I don't know of one tuner that provides multiple tunes for the various uses of a vehicle and if they did, all the tuning would need to be done on a customer's laptop with their software. Then the customer would have to re-flash their PCM in order to switch from tune to tune.

You should either have a tune done in person or have remote tuning done via EFI Live Autocal. IIRC you're around Austin, you could take a trip to Nelson Performance in San Antonio for an in person tune, I don't know any tuners in Austin.

Blackbear offers the Autocal tuning, I have a few friends who have gone that route.
hurricanejake02
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AG
I'm in East Pearland - if you've got a local guy, he's relatively local for me.
1agswitchin4lanes
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Quote:



You should either have a tune done in person or have remote tuning done via EFI Live Autocal. IIRC you're around Austin, you could take a trip to Nelson Performance in San Antonio for an in person tune, I don't know any tuners in Austin.



I had a nelson mail order tune in my truck...ran great!
Silvy
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AG
https://www.facebook.com/HSPTuned/
hotshot.tuning@gmail.com

You can get your truck tuned and if you decide you need more, then you could do longtubes. There would be a re-tune charge after installing headers, but I can't remember what it is.
ShaggyAggie01
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AG
I find it funny that now a 3/4 ton truck with a 7 second 0-60 time is considered a "slug"

I remember drooling over the old 90's model 454SS trucks. they pulled a 7.1 second 0-60.
hurricanejake02
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AG
That 7 second 0-60 time was 9 years and 125,000 miles ago...

I think a lot of it has to do with the torque management. If it was really still a 7ish second 0-60, the first 5 seconds are getting to 20mph, and the last 2ish are getting from 20 to 60.
Silvy
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AG
Torque management and power enrichment are the biggies.

Being that you have a 4L80e, take all that torque management out, son.
hurricanejake02
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AG
It's actually the 6L90 (code MYD)... apparently the six speed makes it tough on the tuners.
Silvy
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AG
Hell yeah pimp, more sweet spots for WOT pulls from a roll.
ShaggyAggie01
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AG
I'm not disputing that a tune would help, just musing about our expectations and how much they have changed with the times.

Back in my college days, I drove a 1990 GMC swb with the 350, and I loved how quick it was. Now I drive a much heavier crew cab truck with a turbocharged 6 cylinder that would blow the doors off of that truck.
CanyonAg77
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AG
So I have a 2000 GMC project truck, needs engine and trans overhaul

2500
6.0
4L80E
3.73 rear

Planned uses: pulling heavy farm trailers and 10,000 pound 5th wheel. I'm already planning aquiring a 4.10 rear. What else do I need to do? Tune? injectors? intake? Throttle body?

Willing to spend some money, just not the $5,000 or so that a turbo or supercharger would cost, or the $15,000 more for a Duramax pickup.
ShaggyAggie01
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AG
I haven't personally done it, but a cam swap is relatively easy for these engines.
CanyonAg77
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Quote:

Blackbear is correct that there's only one tune, it's going to be the tune where you make the most power. I don't know of one tuner that provides multiple tunes for the various uses of a vehicle and if they did, all the tuning would need to be done on a customer's laptop with their software. Then the customer would have to re-flash their PCM in order to switch from tune to tune.
Chevy pickups have the tow/haul button, which, as far as I know, accesses different levels of "tune". Could you not program your PCM that way, so that normal is 'economy', tow/haul is 'performance'?
CanyonAg77
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AG
ShaggyAggie01 said:

I haven't personally done it, but a cam swap is relatively easy for these engines.
Going to overhaul it, so it would be no big deal at all. I assume a chage in injectors, exhaust, intake, tune, etc. would work best if balanced with a different cam.

I have seen some cams supposedly optimized for RV/towing.
Silvy
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AG
You'll need to get a custom tune, but everything else would be fine for what you're doing. As far as a cam goes, you're not going to want anything bigger than a 212/218. The Brian Tooley Racing stage 1 truck cam kit is 206/212 and would likely suit you best, but I recommend contacting the vendor to get their thoughts. Would also ask Cam Motion about their truck cams. With any cam, you're going to need to replace the valve springs.

How much of an overhaul are you talking about? Personally, I wouldn't worry about rod bearings or anything of that nature unless there's an issue in the bottom end. For my 5.3 I mainly just did some cleaning, slammed the cam in, jammed in new lifters, and slapped new gaskets on.

The tow/haul mode only has an affect on the behavior of the transmission and not the performance of the engine. In tow/haul mode can change things like shift points and how the truck holds a gear. For example, in Basic Birch, if I hit the tow/haul switch at 30 MPH, my trans will drop to 1st and hold it there but won't do any bucking if I let off the gas. At 60-70 MPH, it'll do the same thing except it drops down to 2nd gear. This is great for WOT pulls since the trans won't be taking time to downshift and it's not as hard on the transmission (presuming adequate cooling).
CanyonAg77
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AG
The engine has a questionable history. Heck, the whole damn truck has a questionable history. It's the first vehicle I ever owned with a bullet hole in it. There was a baseball bat hidden in the folded up back seat, and an AC/DC dvd in the radio. The guy that I bought it from stopped me before I hauled it off, so he could keep a 6 inch length of chain hanging from the hitch. He told me it was there because it was a white truck, and because the KKK used to drag black people behind trucks with chains....

Multiple oil leaks, something over 200,000 miles. I have to pull the trans, I have to fix the oil leaks, I just figured, why not go through it?

And would I gain any power from bigger injectors, throttle body, etc? What's the best route there?
Silvy
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AG
Example of tow/haul putting in work

Silvy
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AG
You'd need a new intake for a bigger TB and I think the gains would be marginal for you. The injectors you have now are sufficient for your needs, with a bigger injectors you'd only reduce their duty cycle and see no power gains.

While you're there, possibly put on some used 243 heads and bump up compression? Off the top of my head, I think you'd be around 10.5:1.
Silvy
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AG


You can use this as reference, I think everything should be the same except the head gaskets. Depending on what all you buy, you can tweak the vendors around to spend least amount of money. Summit does free shipping on $100+ orders and is typically same or little bit cheaper than Amazon. The head bolts were more of a last minute purchase so O'Reilly's was only option.
ShaggyAggie01
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AG
With the engine's history, id get a runner from a junkyard, or an outfit like this one:
http://www.nolift-motorsports.com/enginetransmission-online-store
CanyonAg77
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AG
I can go through the engine and essentially have a new engine for what it would cost to buy and ship one of those used ones. What am I missing?

And back to modifications, I guess I'm still a little unclear on the recommendations. Sounds like I shouldn't bother with anything regarding intake and fuel? Say I spend $500 on a cam, and it gains me 20-30hp. That sounds like a good return to me. If the same $500 for an intake gains 2-3hp, yeah, wouldn't bother.

Can anyone list mods in order of best return/ must do, down to don't bother?
ShaggyAggie01
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AG
Guess it depends on your capabilities. Machine shop time and over sized pistons, etc. It may be like you say the same price, but also room for mistakes. Rebuilt engines fail pretty often, and require break in measures. If you are comfortable, and experienced with the process, that's your call. If it is your first rebuild, I would not recommend it.
Silvy
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AG
The modifications I would do starting off in your case would be are 243 heads (higher compression ratio), cam, and tune. If there's still more to be desired the Airraid Jr. intake tube will give you a cheap little bump. Headers mainly give you more mid and top end, I don't think they'd be very beneficial in your case.

I wouldn't consider it a rebuilt engine if you're just tearing it apart to ensure all is good, cleaning, and then replacing a few parts & gaskets.

The LS is so easy to tear into, just get after it brah.
Silvy
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AG
Also, I think electric fans would be a worthwhile mod.
agwrangler2001
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AG
6.0 has a 4.00" bore, which means you could upgrade to the later Gen IV square intake port style heads(LS3, etc.)
You could then grab a Gen IV truck intake to accompany it. The newer truck intakes perform much better than the GEN III one you have.


Or you could keep it all Gen III, LS1Tech Classified forum is your friend either way:

https://ls1tech.com/forums/parts-classifieds/1870381-243-heads-ready-install-new-vj-surface-mill-ultrasonic-cleaned.html

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